Generally, a biological, chemical or optical analyzing method of a fluid specimen has been used mainly in the fields of analyzing blood or body fluid taken from a patient in a clinic and diagnosing disease as well as in the chemical or biotechnology fields. In order to provide a small-sized analytical or diagnostic tool capable of analyzing efficiently a fluid specimen various chip structures have been developed and used. As one of these structures, a lab-on-a-chip has been introduced through which various functions are performed in one chip to analyze efficiently a specimen and diagnose disease and further a rapid diagnosis kit can be made.
The lab-on-a chip refers to implementing various experimental procedures performed in a laboratory, for example, separating, refining, mixing, labeling analyzing and washing, etc. of specimens, on a small chip. In a design of the lap-on-a chip, the technologies related to micro-fluidics and a micro-Liquid Handling System (“micro-LHS”) have been mainly used. Additionally, for fabricating a chip structure for implementing micro-fluidics and micro-LHS a chip has been developed and launched on to the market, in which fine channels are formed using a semiconductor circuit design technology.
Typically, an analyzing procedure of a minimum amount of a target-being analyzed substance which is contained within fluid specimens such as blood or body fluid, etc. includes the steps of moving the fluid specimens through a tube-shaped channel formed within a chip and seeing at the course of movement whether the fluid specimens are reacted with proteins of antigens or antibodies, etc. or another protein, which is pre-fixed to the chip, through a detection of fluorescent material. Accordingly, an observing technology of fluid flow moving through the channel provided on a chip, including a fabricating technology of the channel structure, is considered to be one of best essential technologies in the field of manufacturing small sized-chips for performing fluid analysis and acquiring accurate results thereof using the chip.
Referring to a chip (or chip structure) provided with fine channels for implementing micro-fluidics, a small motor for compressing fluid or a capillary phenomenon induced by limiting width and height of the channel for moving the fluid has been used for the fluid to be moved into a space formed within a fine channel inside the chip. At the present, it has been studied that when a main driving force for inducing fluid movement in a chip is capillary force, the fluid flowing through the space formed by channel has an irregular and uneven movement pattern. This result is to be understood that the interaction force between upper-lower inner walls and the fluid, and the other interaction force between left-right inner walls and the fluid are not equal to each other. As a result, this uneven fluid movement pattern becomes a big obstacle to detecting and analyzing the target-being analyzed substance which exists in a minimum amount in a fluid specimen.
Meanwhile, when a chip is configured such that a specimen input hole and a specimen output hole are provided on both ends of a channel so that the fluid inputted to the specimen hole is discharged through a closed-channel such as a tube to the specimen output hole, two upper and lower substrates are fabricated separately and then are connected generally. However, in the case of manufacturing a fine channel structure having a size of less than ten microns according to the prior art, it is not easy to process evenly corners of the channel without loss and further it is difficult to manage product size and control quality when chips are mass-produced. In addition, these minute differences of channel configurations prevent the fluid from being flowed evenly, causing inconsistent specimen analysis results from the chip which is aimed at detecting a trace amount of target-being analyzed substance from a minimum amount of specimen.
Accordingly, need exists for studying and development of a chip for analyzing fluid in which a moving pattern of the fluid is formed evenly and thus bubble creation is decreased and reproducibility thereof is ensured and further a signal detection from a target-being analyzed substance which exists in the fluid is performed easily.